curl POST examples

curl.md

Common Options

-#, --progress-bar Make curl display a simple progress bar instead of the more informational standard meter.

-b, --cookie <name=data> Supply cookie with request. If no =, then specifies the cookie file to use (see -c).

-c, --cookie-jar <file name> File to save response cookies to.

-d, --data <data> Send specified data in POST request. Details provided below.

-f, --fail Fail silently (don't output HTML error form if returned).

-F, --form <name=content> Submit form data.

-H, --header <header> Headers to supply with request.

-i, --include Include HTTP headers in the output.

-I, --head Fetch headers only.

-k, --insecure Allow insecure connections to succeed.

-L, --location Follow redirects.

-o, --output <file> Write output to . Can use --create-dirs in conjunction with this to create any directories specified in the -o path.

-O, --remote-name Write output to file named like the remote file (only writes to current directory).

-s, --silent Silent (quiet) mode. Use with -S to force it to show errors.

-v, --verbose Provide more information (useful for debugging).

-w, --write-out <format> Make curl display information on stdout after a completed transfer. See man page for more details on available variables. Convenient way to force curl to append a newline to output: -w "\n" (can add to ~/.curlrc).

-X, --request The request method to use.

POST

When sending data via a POST or PUT request, two common formats (specified via the Content-Type header) are:

• application/json
• application/x-www-form-urlencoded

Many APIs will accept both formats, so if you're using curl at the command line, it can be a bit easier to use the form urlencoded format instead of json because

• the json format requires a bunch of extra quoting
• curl will send form urlencoded by default, so for json the Content-Type header must be explicitly set

This gist provides examples for using both formats, including how to use sample data files in either format with your curl requests.

curl usage

For sending data with POST and PUT requests, these are common curl options:

• request type

  • -X POST
  • -X PUT

• content type header (single header/multiple headers)

  • -H "Content-Type: application/x-www-form-urlencoded"
  • -H "Content-Type: application/json"
  • -H "Content-Type: application/json" -H "Content-Type: application/x-www-form-urlencoded"

• data

  • form urlencoded: -d "param1=value1&param2=value2" or -d @data.txt
  • json: -d '{"key1":"value1", "key2":"value2"}' or -d @data.json

Examples

POST application/x-www-form-urlencoded

application/x-www-form-urlencoded is the default:

curl -d "param1=value1&param2=value2" -X POST http://localhost:3000/data

explicit:

curl -d "param1=value1&param2=value2" -H "Content-Type: application/x-www-form-urlencoded" -X POST http://localhost:3000/data

with a data file

curl -d "@data.txt" -X POST http://localhost:3000/data
curl -d @filename http://example.com
curl --data-binary @filename http://example.com/

POST application/json

curl -d '{"key1":"value1", "key2":"value2"}' -H "Content-Type: application/json" -X POST http://localhost:3000/data

with a data file

curl -d "@data.json" -X POST http://localhost:3000/data

Read headers from file

curl -H @header_file https://example.com

where the header file is a plain text file with an HTTP header on each line. Like this:

Content-Type: application/json
Content-Type: application/json
Secret: yes
User-Agent: foobar/3000
Name: "Joe Smith"

Download a File

curl -o newfile.tar.gz http://yourdomain.com/yourfile.tar.gz # Save as newfile.tar.gz

Use a Proxy with or without Authentication

curl -x proxy.yourdomain.com:8080 -U user:password -O http://yourdomain.com/yourfile.tar.gz

Store/Send Website Cookies

curl --cookie-jar savedcookies.txt https://www.cnn.com/index.html -O
cat savedcookies.txt
curl --cookie savedcookies.txt https://www.cnn.com

data.json

{
  "key1":"value1",
  "key2":"value2"
}

data.txt

param1=value1&param2=value2

package.json

{
  "name": "postdemo",
  "version": "1.0.0",
  "scripts": {
    "start": "node server.js"
  },
  "dependencies": {
    "body-parser": "^1.15.0",
    "express": "^4.13.4"
  }
}

server.js

var app = require('express')();
var bodyParser = require('body-parser');

app.use(bodyParser.json()); // for parsing application/json
app.use(bodyParser.urlencoded({ extended: true })); // for parsing application/x-www-form-urlencoded

app.post('/data', function (req, res) {
  console.log(req.body);
  res.end();
});

app.listen(3000);